Previous studies have identified 79 and 85 AAT genesin rice genomes (Lu et al. 2012; Zhao et al. 2012). How-ever, the transport activities of the encoded proteinshave rarely been examined. As such, the components re-sponsible for Pro and GABA transport in rice remainunclear. As OsProTs are likely to participate in thesetransport processes and OsProT2 has been characterizedas a functional Pro transporter through its expression inXenopus oocytes (Igarashi et al. 2000), we identified andfunctionally characterized the other two OsProT mem-bers in order to uncover the details for Pro and GABAtransport in rice. Our results demonstrated that plasmamembrane-localized OsProT1 and OsProT3 are func-tional uptake transporters for Pro and GABA in yeastand might get involved in normal growth and stress tol-erance in planta